Transport and Nmr Characteristics of the Skutterdite-Related Compound Ca3Rh4Sn13
C. W. Tseng1*, C. N. Kuo1, B. S. Li2, L. M. Wang3, A. A. Gippius4, Y. K. Kuo2, C. S. Lue1
1Physics, National Cheng Kung University, Tainan, Taiwan
2Physics, National Dong Hwa University, Hualien, Taiwan
3Physica, National Taiwan University, Taipei, Taiwan
4Physics, Lomonosov Moscow State University, Moscow, Russian Federation
* Presenter:C. W. Tseng
We report the electronic properties of the Yb3Rh4Sn13-type single crystalline Ca3Rh4Sn13 by means of the electrical resistivity, Hall coefficient, Seebeck coefficient, thermal conductivity, as well as 119Sn nuclear magnetic resonance (NMR) measurements. The negative sign of the Hall coefficient and Seebeck coefficient at low temperatures suggests that the n-type carriers dominate the electrical transport in Ca3Rh4Sn13, in contrast to the observations in Sr3Rh4Sn13 which has a p-type conduction. Such a finding indicates a significant difference in the electronic features between these two stannides. Furthermore, we analyzed the temperature-dependent 119Sn NMR spin-lattice relaxation rate for Ca3Rh4Sn13, (Sr0.7Ca0.3)3Rh4Sn13, and Sr3Rh4Sn13 to examine the change of the electronic Fermi-level density of states (DOS) in (Sr1-xCax)3Rh4Sn13. It indicates that the Sn 5s partial Fermi-level DOS enhances with increasing the Ca content, being consistent with the trend of the superconducting temperature. With this respect, the NMR analysis provides microscopic evidence for the correlation between the electronic DOS and superconductivity of the (Sr1-xCax)3Rh4Sn13 system.

Keywords: skutterdite-type compound, nuclear magnetic resonance